Tire valve for a pneumatic tire of a vehicle

Abstract

The invention relates to a tyre valve for a pneumatic tyre of a vehicle, having a valve stem extending from the air inlet end to the air outlet end and having an outside thread on its outside circumference and a collar at its air outlet end for a rim well carrying the pneumatic tyre and a fastening thread for an air pressure sensor or other device to be fastened to the valve stem and positioned inside the pneumatic tyre, exhibiting a union nut with an inside thread for screwing onto the outside thread in order to clamp the rim base between the union nut and the collar, with the valve stem being inserted through a rim bore, with a plastic valve cap, with a deformable element located on the outside circumference of the valve stem and/or an inside circumference of the union nut. The tyre valve according to the invention is characterised in that the union nut and, if the deformation element is located on the inside circumference of the union nut, also the deformation element, exhibit a minimum inside diameter that exceeds the maximum outside diameter of the valve cap.

Claims

1. A tyre valve for a pneumatic tyre of a vehicle, comprising: an air inlet end for connection to a source of compressed air and an air outlet end for positioning within a pneumatic tyre; a valve stem extending from the air inlet end to the air outlet end and having an outside thread on an outer surface of the valve stem, a collar at the air outlet end configured to accommodate a rim well carrying the pneumatic tyre, a fastening thread on an inner surface of the valve stem at the air outlet end; a valve cap that is or can be screwed onto the valve stem at the air inlet end, the cap having a maximum outer diameter; a union nut with an inside thread formed on an inner surface of the union nut and dimensioned for the union nut to be screwed onto the outside thread to clamp the rim well between the union nut and the collar, with the valve stem being inserted through a rim bore, wherein the union nut has a minimum inner diameter that exceeds the maximum outer diameter of the valve cap; an annular groove formed either in an inner surface of the union nut at the inside thread, or in the outer surface of the valve stem at a location defined between the air inlet at an outer surface of the rim well, and a deformation element disposed in said annular groove and configured as a) an elastically-deformable ring to be reversibly deformed or b) a plastically-deformable ring to be irreversibly deformed in said annular groove when the union nut is screwed onto the valve such that at an initial bolting torque, a face of the union nut initially abuts the deformation element, and the valve stem is initially rotatable together with the union nut relative to the rim well with the deformation element being substantially deformation-free, and at a subsequent bolting torque, which is greater than the initial bolting torque, the union nut is rotatable relative to the valve stem with the deformation element being deformed in said groove.

2. The tyre according to claim 1, wherein said location is on the outside thread of the valve stem.

3. The tyre valve according to claim 1, wherein the ring is split on its circumference.

4. The tyre valve according to claim 1, wherein when the annular groove is formed in the inner surface of the union nut at the inside thread, the deformation element is detachable from the union nut, and when the annular groove is formed in the outer surface at said location, the deformation element is detachable from the valve stem.

5. The tyre valve according to claim 1, wherein the deformation element is materially bonded to the valve stem.

6. The tyre valve according to claim 1, wherein said inner surface of the valve stem is a surface of a longitudinal bore formed in the valve stem at the air outlet end and the fastening thread is dimensioned to mate with a fastening screw configured to fasten an air pressure sensor to the valve stem when the air pressure sensor is disposed inside the pneumatic tyre.

7. The tyre valve according to claim 6, comprising said fastening screw, wherein the longitudinal bore leads into an air passage extending through the valve stem from the air inlet end to the air outlet end and wherein the fastening screw is designed as a hollow-core screw.

8. The tyre valve according to claim 1, wherein the maximum outer diameter of the valve cap is at least 9 mm.

9. The tyre valve according to claim 1, configured to be operable in cooperation with a rim of a wheel of a utility motor vehicle or a passenger motor vehicle.

10. The tyre valve according to claim 1, wherein the deformation element is said ring made of plastic or rubber.

11. The tyre valve according to claim 1, wherein said ring is split on its circumference with just one split.

12. The tyre valve according to claim 1, wherein the annular groove is formed at the outer surface at said location and said deformation element is configured to be reversibly or irreversibly deformed in said annular groove when the union nut is screwed onto the valve stem to press an end of the union nut, which end is proximal to the rim well, into said deformation element.

Description

(1) The figures show:

(2) FIG. 1 a first example of an embodiment of the invention as viewed from the side and an axial section cut;

(3) FIG. 2 an alternative embodiment of the invention with views as in FIG. 1;

(4) FIG. 3 another alternative embodiment of the invention, with corresponding views;

(5) FIG. 4 a fourth possible embodiment of the invention, again with corresponding views.

(6) FIG. 1 shows a tyre valve according to the invention comprising an air inlet end 1 and an air outlet end 2. The air inlet end 2 is positioned on the side of the rim well 3 that will face the inside of the fitted pneumatic tyre (not shown).

(7) As shown only schematically in the side view, FIG. 1, a fastening screw 7 screwing into a fastening thread 8 at the air outlet end 2 of the valve stem 4 will fasten an air pressure sensor 6 at the air outlet end 2 of the tyre valve or its valve stem 4, the latter exhibiting an air passage 5 extending from air inlet end 1 to air outlet end 2. Item 6 could, however, depict any other device that may need fastening to the tyre valve.

(8) Valve stem 4 has a collar 9 to pull the valve stem 4 against rim well 3 as union nut 10 is screwed onto valve stem 4. Union nut 10 will to this end have a corresponding means for driving, shown here, for example, as external hexagon 11. Union nut 10 has an inside thread 12 and valve stem 4 a matching outside thread 13 to enable screwing on union nut 10. In the example of the embodiment shown in FIG. 1, deformation element 14 in the form of a ring has been fitted to the outside thread 13.

(9) When screwing union nut 10 onto valve stem 4, the face of union nut 10 facing rim well 3 will initially abut deformation element 14, thereby blocking union nut 10 from screwing further down outside thread 13, thereby driving valve stem 4 in the same direction and driving fastening screw 7 into fastening thread 8 until air pressure sensor 6 rests tight against rim well 3 or the face end (air outlet end 2) of valve stem 4, whereafter fastening screw 7 is blocked from screwing down further into fastening thread 8. In general, to prevent fastening screw 7 from rotating in unison with valve stem 4, fastening screw 7 and the housing of air pressure sensor 6 should positively engage. Thereafter, as additional torque deforms deformation element 14 to exceed the corresponding breakaway torque and screw union nut 10 over deformation element 14, union nut 10 will tighten against rim well 3.

(10) A valve cap 15 is screwed onto valve stem 4 at the air inlet end 1. Valve cap 15 has a maximum outside diameter 16 that is smaller than the minimum inside diameter 17 of union nut 10. This allows screwing union nut 10 onto valve stem 4 even with valve cap 15 already screwed onto valve stem 4. The outside diameter of deformation element 14 is correspondingly larger than the maximum outside diameter 16 of valve cap 15 to ensure proper interaction with the minimum inside diameter 17 of union nut 10.

(11) Union nut 10 in the example of an embodiment exhibits a coating or cover 18 at its end abutting rim well 3, i.e. at least on its relevant face, to facilitate tightening union nut 10 against rim well 3 without damaging the surface of the latter and/or to create a corresponding seal. This is not absolutely necessary, however.

(12) The embodiment shown in FIG. 1 furthermore shows a passage 19 branching off from air passage 5 at air outlet end 2, allowing the use of a solid instead of hollow fastening screw 7. Again, this is an arbitrary choice.

(13) The embodiment as shown in FIG. 2 differs from that in FIG. 1 in that deformation element 14 is arranged inside an annular groove 20 on the inside of union nut 10A. The annular groove shown in the embodiment is arranged at the end of the inside thread 12 facing away from air outlet end 2. Again, this is an arbitrary choice. The annular groove 20 could, for instance, also be provided within the axial region of inside thread 12 or at the other end of inside thread 12. The minimum inside diameter 17 of union nut 10 and, in this example of an embodiment, also that of deformation element 14 will again be larger than the maximum outside diameter 16 of valve cap 15.

(14) FIG. 2 does not show the fastening thread and screw and the air pressure sensor.

(15) The example of an embodiment shown in FIG. 3 differs from previously shown embodiments in that deformation element 14 is positioned at the end of union nut 10 facing rim well 3, here in an annular groove 20 in valve stem 4. Union nut 10 will therefore not come to rest against deformation element 14 before it is fully screwed over the outside thread 13 of valve stem 4A. Valve cap 15 again has a maximum outside diameter 16 that is smaller than the minimum inside diameter 17 of union nut 10.

(16) No passage branching from air passage 5 in the region of air outlet end 2 is provided here, as opposed to the embodiments in FIGS. 1 and 2. This is not absolutely necessary, however.

(17) Deformation element 14 in the embodiment shown in FIG. 4 is positioned at the end of union nut 10 facing rim well 3 and attached to said union nut 10B, for instance in an annular groove. The minimum inside diameter 17 of union nut 10B and also that of deformation element 14 will therefore exceed the maximum outside diameter 16 of valve cap 15.